NORTH CHARLESTON -- Officials remain puzzled by the cause of the "electronic odor" some passengers reported smelling in the cabin of an American Airlines flight that made a safe, emergency landing Monday night at Charleston International Airport.

The Busser family from Washington, seated at the plane's rear, described a smell "like a coffee maker overheating" and praised the flight crew's decision to ground the 737 jet.

"We could hear the flight attendants because we were in the back row," said Martha Busser, as she waited for a shuttle at the Sheraton Hotel to take her and her family back to the airport Tuesday morning. "They were very concerned in a professional way."

Passengers first noticed the unusual smell about an hour into Flight 1012 from Miami to Washington, shortly after beverage service Monday night. Busser said the plane landed in Charleston within 20 minutes, about 11:30 p.m.

With no planes available at that hour, American Airlines put up all 160 passengers at local hotels and re-booked them on a flight Tuesday.

American Airlines flew in a mechanic to service the plane Tuesday morning. Company spokesman Ed Martelle said Tuesday afternoon that technicians could not re-create what he described as "an electronic odor."

"We think it will take more time and effort and expertise than we have in Charleston," he said. A crew ferried the plane back to Miami for further study.

Martha and Scott Busser and their daughters, 21-year-old Allie and 11-year-old Cameron, had planned to return home to the Washington area from their Easter vacation in Key West, Fla., Monday night.

Instead, they sat at Charleston International until about 2 a.m. Tuesday, they said, and then waited until about 4:30 a.m. to get settled inside a room.

Pleased overall, Martha Busser said, "I would've been more concerned if they hadn't done anything."